Perceived Brightness Test

The function used here is borrowed from this W3C article where the formula for an RGB color is:
brightness = sqrt( .299 R 2 + .587 G 2 + .114 B 2 )
I have leveled it to a scale of 0-100 and set the reversal threshold to 60 for the Color Brewer pallettes below.

The difference between the two colors is calculated by taking the difference of each respective channel weighted by a coefficient.
.299(maximum(Red) - minimum (Red)) + .587(maximum(Green) - minimum (Green)) + .113(maximum(Blue) - minimum (Blue))
This is also leveled to a scale of 0-100.


Evaluate Colors (Hex or RGB)

Here you can modify this page's foreground and background colors and see the calculated difference in color brightness as well as evaluate it against the static Pallettes below.

Foreground: => Brightness: 0
Background: => Brightness: 100
Difference (0 to 100): 100

Pallette Count Colors